Structure elucidation of the elusive Enzyme I monomer reveals the molecular mechanisms linking oligomerization and enzymatic activity

Enzyme I (EI) is a phosphotransferase enzyme responsible for converting phosphoenolpyruvate (PEP) into pyruvate. This reaction initiates a five-step phosphorylation cascade in the bacterial phosphotransferase (PTS) transduction pathway. Under physiological conditions, EI exists in an equilibrium between a functional dimer and an inactive monomer. The monomer-dimer equilibrium is a crucial factor regulating EI activity and the phosphorylation...